Battery pack thermal energy management assembly and thermal energy management method

Abstract

In some aspects, the techniques described herein relate to a battery pack assembly including a first battery cell group, a second battery cell group, and a multilayered shield disposed along a cell stack axis with the first battery cell group and the second battery cell group. The multilayered shield has an inner layer sandwiched between a first outer layer and a second outer layer. The multilayered shield includes a divider portion disposed axially between the first and second battery cell groups and a folded portion that is folded over the first battery cell group in a first axial direction to axially overlap with an area of the first battery cell group.

What is claimed is: 
     
         1 . A battery pack assembly, comprising:
 a first battery cell group;   a second battery cell group; and   a multilayered shield disposed along a cell stack axis with the first battery cell group and the second battery cell group, the multilayered shield having an inner layer sandwiched between a first outer layer and a second outer layer, the multilayered shield including a divider portion disposed axially between the first and second battery cell groups and a folded portion that is folded over the first battery cell group in a first axial direction to axially overlap with an area of the first battery cell group.   
     
     
         2 . The battery pack assembly of  claim 1 , wherein the multilayered shield is a first multilayered shield, and further comprising a second multilayered shield, the first battery cell group disposed axially between the divider portion of the first multilayered shield and a divider portion of the second multilayered shield, a folded portion of the second multilayered shield folded over the first battery cell group in a second axial direction opposite the first axial direction. 
     
     
         3 . The battery pack assembly of  claim 2 , wherein the folded portion of the first multilayered shield and the folded portion of the second multilayered shield are spaced from the first battery cell group to provide an open area between the first battery cell group and the first and second multilayered shields. 
     
     
         4 . The battery pack assembly of  claim 3 , wherein the second outer layers in the folded portions of the first multilayered shield and the second multilayered shield directly contacts a thermal interface material that is sandwiched between the second outer layers and a portion of a battery pack enclosure. 
     
     
         5 . The battery pack assembly of  claim 4 , wherein the first outer layers in the folded portions of the first multilayered shield and the second multilayered shield separate the open area from another open area established between the battery pack enclosure and the first outer layers. 
     
     
         6 . The battery pack assembly of  claim 5 , wherein the portion of the battery pack enclosure is a second of a battery pack enclosure cover. 
     
     
         7 . The battery pack assembly of  claim 2 , wherein the folded portion of the first multilayered shield and the folded portion of the second multilayered shield span over at least one vent of the first battery cell group. 
     
     
         8 . The battery pack assembly of  claim 2 , wherein the folded portion of the first multilayered shield and the folded portion of the second multilayered shield contact each other. 
     
     
         9 . The battery pack assembly of  claim 2 , wherein the first outer layer in the folded portion of the first multilayered shield contacts the first outer layer in the folded portion of the second multilayered shield. 
     
     
         10 . The battery pack assembly of  claim 2 , further comprising a third multilayered shield, the third multilayered shield having a divider portion directly axially adjacent to the divider portion of the first multilayered shield, the third multilayered shield having a folded portion folded over the second battery cell group in the second axial direction. 
     
     
         11 . The battery pack assembly of  claim 1 , wherein the first and second outer layers are a metal or metal alloy. 
     
     
         12 . The battery pack assembly of  claim 1 , wherein the second outer layer in the folded portion directly contacts a thermal interface material that is sandwiched between the second outer layer and an area of a battery pack enclosure. 
     
     
         13 . The battery pack assembly of  claim 1 , wherein a height of the multilayered shield prior to folding over the folded portion is nominally equal to a height of a battery cell within the first group of battery cells plus two times a thickness of the battery cell plus a thickness of the inner layer. 
     
     
         14 . The battery pack assembly of  claim 1 , wherein the first battery cell group and the second battery cell group each includes at least one battery cell. 
     
     
         15 . The battery pack assembly of  claim 1 , wherein the first battery cell group, the multilayered shield, and the second battery cell group are constituents of a cell stack within a traction battery pack. 
     
     
         16 . A method of managing thermal energy within a battery pack, comprising:
 establishing a divider portion and a folded portion within a multilayered shield; and   positioning the multilayer shield such that the divider portion is between a first group of battery cells and a second group of battery cells along a cell stack axis such the folded portion axially overlaps with an area of the first group of battery cells.   
     
     
         17 . The method of  claim 16 , wherein the multilayered shield is a first multilayered shield, and further comprising establishing a divider portion and a folded portion within a second multilayered shield, and positioning the divider portion of the second multilayered shield along the cell stack axis such that the first group of battery cells is axially between the divider portion of the first multilayered shield and the divider portion of the second multilayered shield. 
     
     
         18 . The method of  claim 17 , wherein, after the positionings, the folded portion of the second multilayered shield extends over the first group of battery cells to contact the folded portion of the second multilayered shield. 
     
     
         19 . The method of  claim 16 , further comprising sandwiching a thermal interface material between the folded portion and an area of a battery pack enclosure.